The present invention concerns regulable dashpots for motor vehicles and a method of adjusting such a dashpot.
Dashpots are manufactured regulable to allow adaptation of a motor vehicle""s performance to given driving and road conditions. Additional regulable bypass valves are accordingly assigned to the shock-absorbing valves in the dashpot""s piston. The regulation is usually carried out by way of electronic programs that control the level of attenuation in accordance with the results of such various measurements as vehicle speed, steering-wheel state, and travel dynamics.
A regulable dashpot is known from German 4 011 358 C1 and GB 2 222 227 A. These dashpots employ a motor to adjust a positioning component. The motor rotates or displaces a bell or rotating component in relation to a main interior bore provided with subsidiary radial bores.
These dashpots have drawbacks. The rotation or displacement requires both powerful adjustment forces and powerful retaining forces in that the rapid flow inside the bypass valve can lead to unintended self-adjustment and especially to total closing. This can have two results. Either the motor or the corresponding magnet is too large to fit inside the dashpot or some or all of the excess heat generated therein is too high to divert. Adjustments accordingly have to be undertaken outside the dashpot itself. This requirement, however, further aggravates the problems encountered in retention and control.
Another regulable dashpot of the genus is known from German 19 850 152 C1. The problems of powerful adjustment and stabilization forces are solved in this dashpot by hydraulically relieving a component of the controls, a stroke piston.
This embodiment, however, has the drawback that the controls component is composed of many parts. It also requires a complicated system of channels and check valves in that the hydraulic relief employs additional channels.
The object of the present invention is a simpler controls component that will demand less powerful adjustment and retaining forces.
The present invention has several advantages. It exploits simple means to keep the adjustment and retaining forces low-powered. Of particular advantage from this aspect is that the valve will have a very high level of self-retention even when the pressure differences are extensive, counteracting any powerful induced adjustment forces.